如何使用GridBagLayout设置JButton大小

Question

I want to set the size of my JButtons that are at the center of my screen to become larger but I can't seem to find how to do that using GridBagLayouts.

Here is how it looks like :

Here is my code :

    //      Client
    c.fill = GridBagConstraints.BOTH;
    c.anchor = GridBagConstraints.CENTER;
    c.gridy = 5;
    c.gridx = 5;
    c.gridwidth = 1;
    c.gridheight = 1;
    c.insets = new Insets(10, 1, 1, 10);
    p.add(b[0], c);

    //      Server
    c.fill = GridBagConstraints.BOTH;
    c.anchor = GridBagConstraints.CENTER;
    c.gridy = 10;
    c.gridx = 5;
    c.gridwidth = 1;
    c.gridheight = 1;
    c.insets = new Insets(10, 1, 1, 10);
    p.add(b[1], c);

I want the buttons to take up a larger portion of the empty space around them.

Answer 1

I can't imagine what do you want, but if you want your button to fill around, you can add

    c.weightx = ...; //Specifies how to distribute extra horizontal space. 
    or c.weighty = ...; //Specifies how to distribute extra vertical space. 

Answer 2

More information was added: Buttons have 50% of the width and [about] 20% of the height of parent [together 50% height including the space in between]. (Slightly rewritten to match the suggestion.)

Solution

Combination of simple Layouts Layouts. Although if you do it like this you will have 3 columns or 3 rows which can't be joined, the rest can easily be changed later:

// row variation

JPanel parent = new JPanel();
parent.setLayout(new GridLayout(3, 1));

parent.add(new JPanel()); // placeholder for 1st row

JPanel row = new JPanel(); // 2nd row
row.setLayout(new GridLayout(1, 3)); // create 3 cells of equal size

row.add(new JPanel()); // 2nd row, 1st cell placeholder

// now you have a 33% x 33% (oops) rectangle in the middle
JPanel controls = new JPanel();
controls.setLayout(new GridLayout(2, 1, 10, 10));
controls.setBorder(BorderFactory.createEmptyBorder(10, 10, 10, 10);
controls.add(new JButton("Client"));
controls.add(new JButton("Server"));

row.add(controls); // add 2nd row, 2nd cell

row.add(new JPanel()); // 2nd row, 3rd cell placeholder

parent.add(row); // add 2nd row

parent.add(new JPanel()); // placeholder for 3rd row

Easy, but you won't be able to join the cells later:

JPanel parent = new JPanel(); parent.setLayout(newGridLayout(9, 9));

Bottom line: combine different layout managers, put your 2 buttons inside a panel and put some placeholders inside, then it should also work fine with GridBagLayout. That said, I would try to stay flexible by writing reusable components which can easily be combined with any layout manager. Then you don't have to use placeholders superfluous code in order to display the components correctly.

Old Answer

Alternative Solution: Use BoxLayout

BoxLayout is more intuitive and easier to understand when looking at code (of course this is only an opinion).

1. Decide how your window is structered (is it more like big horizontal components on top of each other PAGE_AXIS or big vertical components next to each other LINE_AXIS ) and use this as the outer BoxLayout:

    JPanel content = new JPanel(); // or frame content.setLayout(new BoxLayout(content, BoxLayout.LINE_AXIS)); 

2. Add the components along the axis, where you have more than one component along the other axis use a 2nd BoxLayout. You can space components by creating rigid areas (empty rectangles always having the same size) or by adding glue (expanding like gum together with the components).

    content.add(BoxLayout.createHorizntalGlue()); JPanel col = new JPanel(); col.setLayout(new BoxLayout(col, BoxLayout.PAGE_AXIS)); JButton clientBtn = new JButton("Client"); JButton serverBtn = new JButton("Server"); col.add(BoxLayout.createVerticalGlue()); col.add(clientBtn); col.add(BoxLayout.createRigidArea(new Dimension(1, 10))); col.add(serverBtn); col.add(BoxLayout.createVerticalGlue()); content.add(col); content.add(BoxLayout.createHorizontalGlue()); 

Answer 3

button.setMargin( new Insets(50, 50, 50, 50) );

这将为按钮添加额外的空间，并允许布局管理器根据按钮的首选大小来完成其工作。